NXP Semiconductors MCIMX251AJM4A

Overview

MCIMX251AJM4A from NXP Semiconductors (formerly Freescale) is an automotive-grade ARM926EJ-S™ applications processor operating at up to 400 MHz, featuring 128 KB on-chip SRAM, integrated 10/100 Ethernet MAC, dual USB PHYs (HS OTG + FS Host), and AEC-Q100 Grade 3 qualification. It serves as the central compute engine in vehicle infotainment systems for media playback, Bluetooth audio streaming, and touchscreen-based HMI control.

For engineers reviewing the MCIMX251AJM4A datasheet, MCIMX251AJM4A pinout, MCIMX251AJM4A application, or MCIMX251AJM4A equivalent, key selection criteria include its 400 MHz ARM9 core speed, AEC-Q100 Grade 3 qualification, 17×17 mm MAPBGA-400 package with 0.8 mm pitch, integrated DryIce security module, and support for DDR2 memory up to 133 MHz.

Technical Context

The MCIMX251AJM4A implements a single ARM926EJ-S™ core with 16 KB L1 instruction and 16 KB L1 data cache, operates in Little Endian mode only, and integrates a Clock Control Module (CCM) managing doze/wait/stop power modes via selective clock gating. Its Smart DMA (SDMA) engine supports 32 channels for offloading peripheral-to-memory transfers.

It includes dedicated automotive interfaces: two FlexCAN 2.0B controllers, ESAI for digital audio, AUDMUX for flexible audio routing, and TSC+ADC for resistive touchscreen control. Security is enforced via DryIce (tamper-detect RTC, volatile key storage) and IIM (eFuse-based cryptographic key storage).

Key Specifications

Pinout & Package

MCIMX251AJM4A is housed in a 17 × 17 mm, 0.8 mm pitch MAPBGA-400 plastic package (Case 5284), with ball map defined in Table 103 of IMX25AEC Rev. 10. Power, ground, and signal assignments follow Freescale's standardized 400-ball layout for i.MX25 family devices.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive applications processor applications.

Compared with MCIMX255AJM4A and MCIMX253CJM4A, the MCIMX251AJM4A uniquely balances automotive qualification, minimal feature set, and cost efficiency - making it optimal for entry-level infotainment and telematics modules where LCD/Camera interfaces are handled externally.

Availability

MCIMX251AJM4A is available at Aetrix Electronics and suitable for automotive infotainment systems, telematics control units, and driver information displays requiring stable component supply across long production lifecycles.

Supply support for MCIMX251AJM4A includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT markets, with deep expertise in ARM-based application processors and automotive functional safety.

The i.MX25 product line was designed specifically for cost-sensitive automotive infotainment and telematics applications, emphasizing AEC-Q100 compliance, integrated security, and interface flexibility without requiring external PHYs or memory controllers.

FAQ

What is the maximum operating frequency of the MCIMX251AJM4A processor core?

The MCIMX251AJM4A features an ARM926EJ-S™ core rated for operation up to 400 MHz. This maximum frequency is achievable under specified DC operating conditions: core supply voltage (QVDD) between 1.38 V and 1.52 V, and ambient temperature within the AEC-Q100 Grade 3 range (–40°C to +85°C). The device also supports lower-frequency operation (e.g., 266 MHz) at reduced core voltage for power optimization.

Does the MCIMX251AJM4A include an integrated LCD controller?

No, the MCIMX251AJM4A does not include an integrated LCD controller. According to Table 2 in the IMX25AEC datasheet, the LCD Controller (LCDC) is explicitly listed as absent in the MCIMX251 variant. That functionality is only available in the MCIMX255 variant. The MCIMX251AJM4A relies on external display drivers or alternative interfaces such as SLCDC for basic smart LCD panels.

What security features are implemented in the MCIMX251AJM4A?

The MCIMX251AJM4A integrates two primary hardware security blocks: DryIce (providing tamper-detect circuits, battery-backed RTC, and volatile key storage) and IIM (IC Identification Module) for eFuse-based cryptographic key storage and chip identification. These enable secure boot, encrypted firmware updates, and tamper-responsive key erasure - all confirmed in Sections 2 and 3 of the IMX25AEC datasheet.

Is the MCIMX251AJM4A pin-compatible with other i.MX25 family members?

Yes, the MCIMX251AJM4A shares the same 17×17 mm MAPBGA-400 package (Case 5284) and identical ball map (Table 103) with MCIMX255AJM4A, MCIMX251AJM4, and MCIMX255AJM4. All i.MX25 variants in the AJM4/AJM4A suffix group use identical mechanical and electrical pinouts, enabling footprint reuse across different feature sets within the same silicon version.

What is the purpose of the BAT_VDD pin on the MCIMX251AJM4A?

The BAT_VDD pin supplies backup power to the DryIce security module, ensuring continuous operation of the tamper-detect circuitry and RTC during main power loss. As specified in Table 6 and Section 2.1 of the IMX25AEC datasheet, BAT_VDD must be connected to a coin cell or supercapacitor (1.15–1.55 V) to preserve secure keys and time stamps - critical for black box and secure boot applications.